Last January there was a fascinating debate on C-span in which one of the book's authors, Sherif Girgis, debated Andrew Koppelman on 'gay marriage' before an audience at the Harvard Law School. The entire debate can be watched here. Both thinkers have a background in law and have clearly spend considerable time considering the question from their differing perspectives of legal theory. The debate isn't easy-going and can get pretty technical, but it is still definitely worth watching if you have a free hour. This was the most civil and rational debate I have ever seen on this topic which is usually charged with emotion.

If have given some feedback on Koppelman's arguments in the debate here, interacting with his view that marriage is a social construct.